ConvolverNode

let audioCtx = new window.AudioContext();
async function createReverb() {
    let convolver = audioCtx.createConvolver();
    // load impulse response from file
    let response     = await fetch("path/to/impulse-response.wav");
    let arraybuffer  = await response.arrayBuffer();
    convolver.buffer = await audioCtx.decodeAudioData(arraybuffer);
    return convolver;
}
...
let reverb = await createReverb();
// someOtherAudioNode -> reverb -> destination
someOtherAudioNode.connect(reverb);
reverb.connect(audioCtx.destination);